APRIL, 1919. XANTHIUM MILLSPAUGH AND SHERFF. 47 



was the basis of Wallroth's X. oviforme and the identity of the species 

 is thus seen to be settled too clearly to permit of its name being 

 displaced by the more recent name X. silphiifolium}' 



20. XANTHIUM SPECIOSUM Kearney, Bull. Tor. Bot. Club 24: 574, 



1897. 

 X. bubalocarpon Bush, Kept. Missouri Bot. Gard. 17: 123, 



Caulis erectus, robustus, ramosus, ad basim demum 2.5 cm. crassus, 

 plus minusve (infra obtuse et supra acute) quadrangulatus, supra lineis 

 purpureis maculatus, papilloso-scabridus praesertim supra, 1-1.5 m - 

 altus. Folia late triangulato-ovata, obtuse et non profunde 3~5-lobata, 

 dentata, crassiuscula, ad basim cordata, utrinque setulis aut papillis 

 minutis adpressis scabra, petiolis adjectis 1-3.5 <"& longa et 0.8-2.2 dm. 

 lata, petiolis laminis subaequantibus. Fructus (PI. VII, f. 20; PI. X, 

 ff . 4-6) maximi, ovoidei aut conici; corpore ovato-cylindrico, vix aspecta- 

 bili, glanduloso-pubescenti, aculeis armato, demum circum 2-2.3 mm - 

 longo et 7-8 mm. crasso; rostris attenuatis, hispidis, subrectis aut 

 incurvatis, ad apicem hamosis, 6-n mm. longis; aculeis confertis, sub- 

 tenuibus, besse inferiore aut dimidio inferiore hispido, versus apicem 

 levibus, ad apicem hamosis, plerumque 7-9 mm. longis; toto fructu 

 (aculeis et rostris adjectis) demum 3-4 cm. longis et 2-2.5 (~3 ex descrip- 

 tionibus Kearneyi et Bushii) cm. latis. 



DISTRIBUTION: Tennessee to South Dakota, Texas and Mexico; 

 adventive in Maine and Vermont. 3 



SPECIMENS EXAMINED:* MAINE: North Berwick, wool-waste heap, 

 Sept., 1895, John C. Parlin (Hb. Gray). TENNESSEE: Cocke County, 

 between Paint Rock and Del Rio, along French Broad River, Thos. H. 

 Kearney, Jr., 785 (Hb. Greene 19829; Hb. Mo. 85550; Hb. N. Y.; 

 cotypes). MISSOURI: Cass County, roadside, prairie, Aug., 1869, G. C. 



1 Since the above was written, we have been very fortunate in receiving from 

 the Herbaria of the British Museum of Natural History and the Royal Botanical 

 Gardens at Kew, excellent photographs of the Douglas plants. Our conclusions, as 

 presented above, are seen to be confirmed most emphatically. Both specimens match 

 precisely the Suksdorf material of X. silphiifolium. The inscription on the British 

 Museum sheet, as copied for us, reads, "X. strumarium Willd. Sandy island and 

 banks of the Columbia Douglas 1825 Xanthium canadense Spreng. Hook Fl. Bor.- 

 Am. i. p. 308." That upcn the sheet at Kew (a sheet originally in Bentham's private 

 herbarium) reads, "Xanthium canadense Spr. Hook Fl. Bor. Am. I. 308. Am. bor. 

 occ. Douglas 1829 [sic] X. oviforme Wallr. cotype." 



2 Piper (Contrib. U. S. Nat. Herb. 1 1 : 550. 1906) has referred X. silphiifolium 

 Greene to this species. But, as will be apparent from the foregoing paragraphs 

 (C/. X. oviforme, p. 44) if X. silphiifolium, which is synonomous with X. oviforme, 

 shall subsequently be proved conspecific with X. speciosum, then, by the same proof, 

 X. speciosum will have been shown to be synonomous with X. oviforme. 



* Cf. footnote i, p. 27. 



4 We have seen two specimens by H. Eggert, one at least from Illinois (pre- 

 sumably at East St. Louis), collected Sept. 13, 1874 (Hb. Gray; Hb. Mo. 85381). 

 These appear to be X. speciosum, but the prickles are subremote and rather stout and 

 suggest X. oviforme Wallr. very strongly. 



